Method of uniting wax fabrics



Dec. 19, 1933.

s. MOORE mm'non OF UNITING WAX FABRICS Filed March 16. 1952 2Shets-Sheet 1 mm SZWZ Moore.

Dec. 19, 1933. s MOQRE 1,940,559

METHOD OF UNITING WAX FABRICS Filed March 16. 1932 2 Sheets-Sheet 2Patented Dec, 19, 1933 METHOD OF UNITING WAX FABRICS Stuart Moore, mu,Tex ssignmto Dixie Wax Paper Company, Inc., Dallas, Tex., a cornotationof Texas Application March is, 1932. Serial No. 599,323

3 Claims. (01.15442) The present invention pertains to the art of makingbags of paper or other flexible material adapted to such use, which havebeen previously coated on one or both sides with wax, parailine, orsimilar moistureproof coatings in order to render the bags resistant orimpervious to grease or moisture, and which coating will also excludeair and retard the escape of the flavor or aroma of the food contentsstored within the bags. The invention further relates to a novel methodfor uniting and sealing the joints or edges of such coated papers orfabrics.

Heretofore, it has not been commercially feasible to manufacture bags ofglassine paper or other papers coated with parafiine wax or othercoating substance, because no method was known for effecting the rapidand proper penetration of the glue, paste or other adhesive necessaryfor securely affixing or uniting the overlapping edges of the sides andbottoms of bags. However, the application of heat to wax coated papersand fabrics has been known for melting the wax coated upon such papersor fabrics in order that when the wax cools, it will congeal and therebycause a temporary connection. Also, the application of heat has beenemployed for uniting the edges of wax coated paper to which glue hasbeen previously applied, in order that the heat will melt the waxcoating and permit the glue to come in contact with the paper or fabric,and subsequently, applying pressure to the paper or fabric to hold thepaper sections together until the glue has set, but each of these knownmethods of uniting and sealing wax papers together have provenunsatisfactory in the making of bags, as the joints so formed are not ofsufficient strength as to permit the bags to retain the articles storedtherein.

Amongst the principal objects of the present invention is to provide anovel method of manufacturing bags by securing a sufficiently strongjoint between the overlapping edges and folds of the paper to beconnected and forming a seal about such joint by the application of heatat the point of contact of the edges of the paper to be connected,whereby a sealed joint will be effected, having greater strength thanthat of the paper employed.

Other objects of the invention will be in part obvious and in partpointed out hereinafter.

In order that the invention and its mode of operation may be readilyunderstood by'persons skilled in the art, I have in the accompanyingillustrative drawings and in the detailed following description basedthereon, set out several possible embodiments of the same.

In these drawingsz-e- Figure 1 is a fragmentary view in vertical sectionof a conventional type of bag making machine, illustrating how theapparatus for carrying out my invention may be installed thereon;

Figure 2 is an enlarged detail section of the same bag making machineshowing in side elevation the heaters for effecting a seal between thelongitudinal edges of a web of paper after the latter has been formedinto a flat tube;

Figure 3 is a detail elevation of a tympan or packing cylinder of thebag making machine showing another form of heater applied thereto andits connection with a suitable source of electrical energy, which latterhas been diagrammatically shown;

Figure 4 is an end elevation of the heaters as illustrated in Figure}with the flat tube of waxed paper passing therebetween;

Figure 5 is an enlarged detail end elevation of the packing cylinder andan adjacent plate cyl inder of the printing mechanism showing, in endelevation, one of the heaters arranged within the packing cylinder andthe path of travel of the paper bags between the cylinders;

Figure 6 is an enlarged longitudinal section through one of the fiatheaters;

Figure 7 is a transverse section through the same and Figure 8 is avertical transverse section through the upper adjustable heater asbetter shown in Figures 2 and 4; of the drawings.

Referring now more particularly to the accompanying drawings whereinlike correspond-- ing parts are designated by similar referencecharacters throughout the several views, I have ,shown a conventionaltype of bag making machine comprising a frame 1 supporting at one end,thereof, a roll 2 of paper from Whichthe bags are formed. The web 3 ofpaper from this roll, and which is, to be formed into bags, passes overthe usual paste supplying roll 4 whereby the paste is applied to one ofthe longitudinal edges of this web of paper. This web 3 progresses abouta suitable forming element 5 and thence to the bite of a pair of feedrolls 6 which are effective to advance the web and ensure itsprogressive folding into a flat tube from the forming element 5. Thepasted edge, when the web is folded, overlaps the adjacent folded edgeof the web and affords a longitudinal seam for the tube, as usual. Thepaper tube so formed, after passing through the usual feed and catchrolls, comes in contact with the usual severing device, which lattersevers the tube in bag lengths in a successive manner. The roll 7supplies paste to the margin of the leading end of each succeeding tubeor bag section so severed. Each bag section, now having the longitudinalseam properly sealed and having a streak of paste along the leading endthereof, is fed to the usual con veyor 8 where the forward end of eachtube is folded over and subsequently fed between the packing cylinder 9and the plate cylinders w of.

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the usual printing mechanism associated with the bag making machinewhereupon the lace oi. each bag may'have the required printed matterthereupon. Each bag so formed and printed is then delivered to the upperpart 0! the conveyor 8 and finally discharged in its completed form toone side of the bag making machine. The foregoing briefly describes themethod of forming bags from an ordinary paper bag making machine nowextensively used, and the same forms no part of the present invention.

The application of glue to the longitudinal edges as well as the ends ofbags so formed by a bag making machine oi the kind above set forth, hasproven very satisfactory where ordinary paper is employed, but whereglassine or other paper having a coating of wax or oil is employed. thebond or seal between the longitudinal edges and ends of each bag asformed does not permit of the generaluse of such bags as is now requiredin the use of ordinary paper bags which contain no moistureprooicoatings. Heretoiore the application of heat has been made to the seamsand edges of wax coated papers, whereupon the heat will soften orliqueiy the wax in order that by merging and adherence of the coating, aseal may be effected. Still additional methods and processes of scamingor uniting the edges of wax papers or fabrics have been used, whichconsist in applying an adhesive to that portion or edges of the coatedpapers to be connected, and then applying suflicient heat thereto tomelt the wax or other coating and also supplying suflicient pressure tohold the edges of the paper together until the adhesive has set and thewax congealed, and yet the bags or other containers so formed do nothave a strong and effective bond or seal at the seams or edges of thebags as to permit such moistureproof or wax coated bags to be of generaluse.

In carrying out my invention, I have found that by the properapplication of heat without the use of pressure to the edges or seams ofpaper previously waxed or coated with a moistureproof material, may bereadily united and a sufiiciently strong seal or, bond established thatwill permit thebags so formed to be employed for general use. Such waxcoated paper should be substituted for the roll 2 of the ordinaryuncoated paper and the web of wax coated paper is first supplied with asuitable paste or adhesive along its longitudinal edges by means of thepaste applying roll indicated by the numeral 4 upon the drawings. Thetube so formed with the adhesive thereupon passes between the heaters 11and 12 whereupon the wax or other coating upon the paper is first meltedto liquid form and the glue placed thereupon permitted to flow intocontact with the paper. By the continual and simultaneous application.of heat, the cells or pores of the paper have a tendency to expandwhereupon the adhesive can be more readi- 1y absorbed by the fibersthereof especially in the absence of pressure and thus enhance thestrength of adherence. These heaters 11 and 12 being-relatively longpermit of the application of heat to the paper for a relatively longperiod of time, whereupon by this continual application of heat to theadhesive, the moisture contained in the latter is more readilyevaporated and the adhesive permitted to set in a relatively shortperiod of .time. As the web of paper progresses beyond the heaters 11and 12, it will readily begin to cool, whereupon the Wax so melted aboutthe bond or seal so made will con geal, thereby elIecting amoistureprooi. seal about the connected edges of the paper. In order toeffect a similar seal between one of the open ends of each bag sectionand. permit 01' the proper application of heat, 1 preferably mountwithin the outer periphery of the packing cylinder 9, the heaters 13.Each one of these heaters 13 is so arranged and the packing cylinder sotimed that a heater 13 will come in contact with that end of the bag tobe sealed and stays in contact with such end of the bag until thepacking cylinder has made one-half of a complete revolution, which is ofsumcient time to permit first of the melting of the wax at that point ofthe bag to which the second or end seal is to be effected, permittingthe paste which has been applied to that end of the bag by the pasteapplying apparatus 7 to come in contact with the paper and subsequently,by the continual application of heat to the paper, the pores thereofwill expand or the fibers thereof separated in order that the adhesivewill be more readily absorbed and as the paper bag so formed leaves thepacking cylinder, it will be permitted to cool whereupon thewax whichhas been previously melted, will congeal so as to establish amoisture-proof coating about the seal so made. By applying heat andwithout applying pressure to the wax coated papers as they pass betweenthe heaters 11 and 12 or in contact with the heater 13 in the manneraforesaid, I have found that a truly moistureproof bag is formed withsealed joints of greater strength than that of the paper so employed inthe making of the bags.

Whereas the heaters as shown in the accompanying drawings are suppliedwith electrical energy, it is, of course, to be understood that heatderived from gas, chemicals, steam, heated water, or other liquids, maybe used. While the degree or intensity of heat necessary to effectuniting or sealing varies with the amount of wax or other coatingmaterial which has been applied to the paper from which the bags areformed, the requisite and proper intensity may be secured by any commonor well known meth- 0d of controlling the electrical current or otherheating medium. These heaters are each formed from a tube 14 preferablymade from copper. The length and width, together with the thickness ofthe tube, may be varied to meet the particular requirements of the typeof bag to be manufactured, or the type of bag making machine used, aswell as the heating element employed. Positioned within the tube 14 is aresistance coil 15 which is bent upon itself, the two sections thusformed are separated by an asbestos partition 16 and the electricalenergy is supplied to this element 15 through the conductors 1'7.Surrounding this element 15 and positioned within each tube, is anenvelope of asbestos 18, whereas the opposite ends of the tube areclosed by suitable sealing material 19. The heaters 13 are of the sameouter contour as the heater 12 and these heaters 13 are each fastenedWithin a suitable transversely extending channel or recess 20 formedwithin the outer periphery of the packing cylinder 9. The heaters 13, asillustrated in Figure 1 of the drawings, are arranged diametricallyopposite within the outer periphery of the packing cylinder 9 so thatwhen the cylinder is revolved, one heater contacts the bottom fold orseam of the bag, the heat therefrom penetrates and heats the adhesivewhich has been previously applied to the being in contact with theconductor rings 21' secured upon an extension of the cylinder 9 andthese conductor rings 21 are electrically con-- nected by means of theconductors 21 to a suitable source of electrical energy herein indicatedby the numeral 22. Electrically arranged within the conductors 21 is arheostat 23 or other suitable control, whereby the flow of current tothe element within the heater 13 may be controlled so that the propertemperature may be automatically or manually maintained.

The heater 12 is supported upon the bed plate 21.01 the bag makingmachine and held in proper position by means of the clamps 25. The upperheater 11 has secured to one end thereof, a bracket 26 and this bracket26 is adjustably connected by means of the set screw 27 to the frame 1of the bag making machine, whereas the opposite end of this heater 11 iscurved or bent upwardly as at 28. The bent or free end 28 of this heater11 permits the web of paper which is to be formed into bags to readilypass between the heaters 11 and 12 and the vertical adjustment of thisheater 11 may be readily established in order to cause the same to beretained in proper position above the seams of the paper web, which areto be sealed together.

The web of paper, as it leaves the former 5 is folded upon itself in theshape of a tube, as is better illustrated in Figure 4 of the drawings,and the overlapping longitudinal edges of the paper form a seam which isto be secured together by means of the adhesive 29. This adhesive hasbeen applied to the paper as it passes over the paste supplying roll 4and the paper tube, together with the seam so formed, passes between theheaters 11 and 12 in order that the heat will be applied directly to theopposite sides of the paper at a restricted longitudinal area or zone.This seam or area to be sealed or united travels the full length of theheaters 11 and 12 in order that the heat will first melt or liquefy thewax coating upon the paper, and.

as the paper progresses between these heaters, the uniting and sealingoperation heretofore described, will be completed. As the folded overend 30 of each bag section illustrated in Figure 5 comes in contact witha heater 13, the heat so generated will perform a similar action uponthis end of the bag to be sealed, as when the longitudinal seam passesbetween the heaters 11 and 12 in order, at this point or end of the bag,the proper sealing and uniting will be effected. That portion of thepaper having the adhesive thereon as it comes in contact with theheaters 11, 12 or 13, is not subjected to pressure as is apparent fromFigures 4 and 5 of the drawings nor is pressure desired during eithersealing operation.

The application of the invention heretofore described is not limited tobags in which the opposite edges thereof consist of a single fold, or inwhich one end is folded onto an adjoining portion of, the bag structureto close the same. but may be employed in the manufacture of bags of anyother of the known types of structures. For example, the invention maybe employed to manufacture a bag wherein the opposite edges thereofconsist of two or more pleats'or folds, and-also may be employed in themanufacture of bags in which the bottom and top ends thereof are or maybe closed, in an altogether different manner from that described; by theapplication ofheatto the adhesive and paper at the proper and necessarypoint of adherence. It is also to be understood that the method andapparatus herein shown and described are not limited for use inconnection with paper bag making but the same may be employed foruniting any paper or fabric having an adhesive repellant coatingthereupon.

Manifestly, the construction herein shown is capable of considerablemodification and such modifications as come within the scope of myclaims, I consider within the spirit of my invention.

I claim:-

1. The method of uniting wax coated paper which consists in applying anadhesive to that portion of the paper to be united, subjecting to heatthat portion of the paper having the adhesive thereon whereby the waxwill be melted to liquid form, the adhesive permitted to flow intocontact with the paper, the cells or pores of the paper expanded topermit of the absorption of the adhesive, and the drying ofthe adhesivewhen absorbed by the paper all without the application of pressure andsubsequently withdrawing the heat for permitting the wax to congealabout that portion of the paper so united.

2. The method of sealing wax coated papers which consists in applying anadhesive to that portion of the papers to be sealed together, subjectingthat portion of the papers having the adhesive thereon directly to heatand without pressure whereby the wax will melt and the adhesive bepermitted to come in contact with the paper, continually applying heatto the paper whereby the fibers thereof will absorb the ad-.-

hesive and the adhesive being further subjected to a drying action bythe heat so applied, and withdrawing the heat, whereby the wax willcongeal about that portion of the paper united together.

3. The method of sealing the seams of paper bags formed from wax coatedpaper which consists in overlapping the edges of a sheet of paper toform a seam, applying an adhesive to said seam, passing the seam withthe adhesive thereon between relatively long spaced heaters whereby heatmay be applied to the opposite sides of the seam for melting the wax andadhesive to liquid form without the application of pressure, continuallyand simultaneously applying the heat to the seam whereby. the adhesivewill be permitted to flow in direct contact with the paper, the cells orpores of the paper being expanded to permit the absorption of theadhesive, and drying the adhesive when absorbed. by the paper, theentire action of the heaters being without the application of pressureand subsequently withdrawing the heat for permitting the wax to congealabout that portion 01' the paper so united.

- STUART MOORE.

